What compelled me to take my mother’s mystery houseplant, I don’t recall. Its smooth, reed-like fronds grew outward from a single, papery stalk in the shape of a fan. My mother kept it in a plastic pot – the kind in which you might bring home a tomato plant from a nursery. Nothing showy. And the plant wasn’t either. “Give it a little water once a week,” Mom said, forgetting what it was called. “It blooms once every year or so, but if you’re patient, the flowers are spectacular.”

I was feeling unusually down this week, more than even dreary skies and freezing drizzle could account for. Tuesday, I didn’t want to go out. But needing to do errands, I zipped my rain jacket, buckled my kids in the van, and drove to Bath anyway. “What’s the date?” I asked my 15-year-old daughter, Lydia, pulling up to the bank. “April 17th,” she said. “Oh.” I sighed. Suddenly my heavy mood made sense. “Ruth’s birthday.”

Is there anything much sweeter than a baby announcement? Who doesn’t love receiving a card in the mail with the pucker-faced picture of a relative or friend’s new arrival? I enjoy posting such proclamations on the fridge, eager to share the good news with any unsuspecting visitors who may walk through my door. So it was when a baby announcement reached a Judean hillside long ago. Only, this message didn’t arrive via a rural mail carrier. It arrived with an eruption of light via a heavenly angel. Friends and relatives weren’t the recipients, but a band of frightened, uneducated shepherds watching over their flocks.

Early last spring, I mentioned my need to grow things to one of my late daughter’s teachers. It’s that backward pull again, the roots of childhood lacing up my legs like pea vines. I’d felt it for years–this need to plant–but it was...